Malignancy risk of thyroid nodules with nonshadowing echogenic foci

Purpose

This study was conducted to determine the malignancy risk and diagnostic value of various types of nonshadowing echogenic foci (NEF) in the risk stratification of thyroid nodules.

Methods

A total of 1,018 consecutive thyroid nodules (≥1 cm) with final diagnoses were included. The presence of NEF was determined and types of NEF were classified according to the presence of a comet tail artifact (CTA), location, and size through a prospective evaluation. The associations with malignancy, malignancy risk, and diagnostic value of various types of NEF were assessed.

Results

Intrasolid punctate NEF without CTA was the only type of NEF that was an independent predictor of malignancy (P<0.001). The malignancy risk of intrasolid punctate NEF without CTA was substantially higher in solid hypoechoic nodules than in isoechoic or nonsolid nodules (71.3% vs. 9.2%, P<0.001). In solid hypoechoic nodules, slightly increased sensitivity (70.8% vs. 67.9%) for malignancy and a similar malignancy risk (71.4% vs. 71.3%) were observed for intrasolid punctate NEF (with or without CTA) and intrasolid punctate NEF without CTA, respectively. NEF with CTA at the margin of the cystic component was not associated with malignancy or benignity in nonsolid nodules (P>0.05).

Conclusion

Intrasolid punctate NEF without CTA was the only independent predictor of malignancy. However, solid hypoechoic nodules with intrasolid punctate NEF should be classified as high-suspicion nodules regardless of coexisting CTA. Other types of NEF had no added value for detecting malignancy compared to intrasolid punctate NEF without CTA.

Malignancy rates for Bethesda III and IV thyroid nodules: a retrospective study of the correlation between fine-needle aspiration cytology and histopathology

BACKGROUND

Fine-needle aspiration cytology (FNAC) has become a well-established modality in the diagnosis, staging and follow-up of thyroid nodules. FNAC outcomes are routinely classified using the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), facilitating appropriate clinical management. Bethesda categories III and IV encompass varying risks of malignancy. This retrospective study established a possible association between these cytological categories and malignancy rates in patients treated at a single institution.

METHODS

Over a 6-year period, 11,627 FNAC procedures were performed on thyroid nodules. Of these, 814 (59.63%) patients were submitted to thyroidectomy. The nodules of 108 patients were classified as Bethesda category III and 47 patients as Bethesda category IV. Patient data were reviewed to establish a correlation between the FNAC results and the final histopathological analyses.

RESULTS

The rates of malignancy among patients who underwent surgery were 25% for category III and 27.6% for category IV, with no significant differences between categories (p = 0.67). The pathological parameters of malignant nodules, namely tumour type, size, encapsulation, invasion into the thyroid capsule, extrathyroidal extension and lymphovascular invasion did not significantly differ between the groups (p > 0.05).

CONCLUSIONS

This paper provides a more precise correlation of malignancy rates with thyroid nodules classified as Bethesda categories III and IV, as our findings are comparable to the literature, giving malignancy rates ranging from 10 to 30% for category III and 25-40% for category IV. Use of the BSRTC is heterogeneous across institutions, and there is some degree of subjectivity in the distinction between categories III and IV; therefore, it is crucial to estimate the rates of malignancy at each institution. Molecular assays are of increasing importance in determining the need for surgical intervention for thyroid lesions. Gene expression assays using FNAC material may demonstrate a high predictive value for cytologically indeterminate thyroid nodules diagnosed as Bethesda classes III and IV.

Computer-aided diagnostic system for thyroid nodule sonographic evaluation outperforms the specificity of less experienced examiners

PURPOSE

Computer-aided diagnosis (CAD) may improve interobserver agreement in the risk stratification of thyroid nodules. This study aims to evaluate the performance of the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) classification as estimated by an expert radiologist, a senior resident, a medical student, and a CAD system, as well as the interobserver agreement among them.

METHODS

Between July 2016 and 2018, 107 nodules (size 5-40 mm, 27 malignant) were classified according to the K-TIRADS by an expert radiologist and CAD software. A third-year resident and a medical student with basic imaging training, both blinded to previous findings, retrospectively estimated the K-TIRADS classification. The diagnostic performance was calculated, including sensitivity, specificity, positive and negative predictive values, and the area under the receiver operating characteristic curve.

RESULTS

The CAD system and the expert achieved a sensitivity of 70.37% (95% CI 49.82-86.25%) and 81.48% (61.92-93.7%) and a specificity of 87.50% (78.21-93.84%) and 88.75% (79.72-94.72%), respectively. The specificity of the student was significantly lower (76.25% [65.42-85.05%], p = 0.02).

CONCLUSION

In our opinion, the CAD evaluation of thyroid nodules stratification risk has a potential role in a didactic field and does not play a real and effective role in the clinical field, where not only images but also specialistic medical practice is fundamental to achieve a diagnosis based on family history, genetics, lab tests, and so on. The CAD system may be useful for less experienced operators as its specificity was significantly higher.

Outpatient thyroidectomy in the pediatric population

Preoperative optimization and patient education have allowed for the transition of thyroid surgery to the outpatient setting over the last few decades. Performing these operations in the outpatient setting has proven to be cost-effective and safe in the adult population. The purpose of this study is to evaluate the safety and efficacy of outpatient thyroid surgery in the pediatric population. A retrospective review from December 2015 to February 2019 of patients under the age of 18 years of age undergoing thyroidectomy performed by two endocrine surgeons at a large academic was performed. There were 55 consecutive operations performed in 51 patients for thyroid pathology, two were excluded as they were inpatient procedures. Cases were reviewed for complications, unplanned same-day admission, 30-day admission, unplanned reoperation, and death. Mean age was 15 ± 0.3 years (range 9-18 years), 79% of the patients were female. Operations were performed for Graves' disease (n = 29), thyroid cancer (n = 9), thyroid nodule (n = 6), multinodular goiter (n = 4), Hashimoto's disease (n = 3), and toxic adenoma (n = 2). Operations performed included: total thyroidectomy (n = 36), thyroid lobectomy (n = 13), total thyroidectomy with lymph node dissection (n = 2), and lateral neck dissection (n = 2). All patients were discharged home within 6 h after completion of the operation. Five (9.4%) patients had transient hypoparathyroidism, with parathyroid hormone levels <10 pg/mL immediately postoperatively. One patient (1.9%) developed a postoperative hematoma on postoperative day six and required reoperation and readmission. Two patients (3.8%) had permanent hypoparathyroidism and one had transient hoarseness (1.9%). There were otherwise no readmissions or ED visits. In conclusion, outpatient thyroid surgery is safe and effective for pediatric patients.

Radiofrequency ablation of functioning and non-functioning thyroid nodules: a single institution 12-month survey

PURPOSE

Radiofrequency (RF) treatment has played an increasing role in the management of benign thyroid nodules in recent years. The aim of this retrospective study was to evaluate the efficacy of RF treatment on volume reduction in functioning and non-functioning thyroid nodules.

PATIENTS AND METHODS

We reviewed the medical records of patients who had thyroid nodule RF ablation at our department between August 2017 and May 2018. Patients underwent a periodical follow-up with ultrasound examinations and thyroid function tests at 1, 3, 6 and 12 months from RF. Complications were assessed using the reporting standards of Interventional societies.

RESULTS

43 patients were submitted to thyroid nodule RF ablation treatment. Patients were subdivided into two groups, those with functioning (17 patients) or non-functioning nodules. At baseline (i.e. pre-RF treatment), the two groups of patients were superimposable for gender, age, BMI, nodule volume and maximum nodule diameter. The volume reduction of all 43 nodules was 69.1 ± 17.3% (range 26.0-94.5%) with no difference between functioning and non-functioning lesions (72.9 ± 18.1% vs 66.7 ± 16.7%, p = 0.254). A total energy delivered per nodule was 16.5 ± 6.8 kJ, with no difference between functioning and non-functioning lesions (14.5 ± 7.2 kJ vs. 18.2 ± 6.3 kJ, p = 0.083, respectively). No major complications were observed.

CONCLUSIONS

Radiofrequency ablation is a clinically effective and safe outpatient treatment in patients with benign nodules. In particular, we showed that a single treatment is effective in restoring euthyroidism in patients with autonomously functioning thyroid nodules.

Monocyte-to-high-density lipoprotein cholesterol ratio is associated with the presence and size of thyroid nodule irrespective of the gender

Background

Systemic inflammation may be involved in the formation and progression of thyroid nodule (TN). The aim of this large-scale study was to investigate the association of several simple inflammatory markers with the presence and size of TN.

Methods

A total of 133,698 adults were included for the current analysis. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and monocyte-to-high-density lipoprotein cholesterol ratio (MHR) were calculated. The logistic regression was used to explore the association of the four markers with the presence and size of TN.

Results

The prevalence of TN was 55.1% among females and 44% among males; 13% of women and 8% of men had non-micronodule. In women, MHR and PLR were significantly associated with the presence of TN and non-micronodule; in men, MHR and NLR were significantly associated with the presence of TN and non-micronodule.

Conclusions

As a low-cost, simple, and reproducible inflammatory marker, MHR is strongly associated with the presence and size of TN irrespective of the gender.

A challenging case of Mesenchymal Chondrosarcoma involving the thyroid and special considerations for diagnosis

Background

Thyroid ultrasound is usually used to risk-stratify incidental thyroid nodules. Nodules with high risk sonographic features for malignancy are evaluated by fine-needle aspiration. The role of core needle biopsy for thyroid nodules is limited to cases where the fine needle aspiration is inconclusive.

Case presentation

We describe a rare case of mesenchymal chondrosarcoma of the thyroid gland with uncertain primary origin. Thyroid ultrasound showed right sided large, solid, hypoechoic nodule with calcifications and peripheral vascularity and unremarkable isthmus and left thyroid lobe. Fine needle aspiration of the right nodule suggested lymphocytic thyroiditis. The sonographic findings contradicted the typical bilateral clinical and sonographic picture of lymphocytic thyroiditis. A core needle biopsy showed mesenchymal chondrosarcoma.

Conclusion

This case highlights the importance of correlating pathologic diagnosis with sonographic findings, the appropriate utilization of fine needle aspiration and core needle biopsy to evaluate thyroid nodules and the rare incidence of mesenchymal chondrosarcoma involving the thyroid.

Diagnostic value of shear wave sonoelastography in differentiation of benign from malignant thyroid nodules

PURPOSE

To study the efficacy of shear wave elastography (SWE), using both qualitative and quantitative methods, alone and in conjunction with other B-mode features.

METHOD

117 patients with 123 nodules were studied both by conventional ultrasonography and SWE. Size, echogenicity, margins, internal calcification (micro- or macro-calcification), composition, shape and color Doppler were assessed for each nodule. The elasticity was assessed both qualitatively and quantitatively. Velocity in the ROI (Region of Interest) was calculated in the stiffest portions for 3 times, and maximum and mean velocity were obtained. ROC curve was analyzed to calculate the best cut-off value of the SWV (Shear Wave Velocity). Univariate logistic regression was used to examine the maximum and mean SWV as discrete variables and the results were compared to key variables of conventional US (Ultrasound) features.

RESULT

123 nodules in 117 patients were evaluated. Poor margins, hypoechogenicity, micro-calcification, color Doppler grades III and IV, color map grades IV and V, maximum and minimum velocity had significant correlation with malignancy. The highest Nagelkerke R2 belonged to maximum and mean velocity (R2 = 41.2 and 39 respectively) which propose them as the strongest predictors of malignancy. The best cut-off point for differentiation of benign from malignant nodules was 3.63 m/s for maximum velocity (sensitivity of 90 %, specificity of 78.2 %,) and 3.44 m/s for mean velocity (sensitivity of 90 %, specificity of 76.4 %).

CONCLUSION

The Real-time SWE is a promising test for the preoperative malignancy risk stratification of patients and maximum velocity has the strongest predictive value for both conventional and elastography variables.

McGill Thyroid Nodule Score in Differentiating Thyroid Nodules in Total Thyroidectomy Cases of Indeterminate Nodules

Fine-needle aspiration biopsy (FNAB) is the first-line modality in the evaluation of thyroid nodules. However, the results of indeterminate pathology place the thyroid surgeon in difficult management situations. This study evaluates McGill Thyroid Nodule Score (MTNS) to identify thyroid nodules that harbor malignancy in cases of indeterminate FNABs and to guide surgeon about the need and extent of surgery. We conducted a retrospective chart review of 344 patients who underwent total thyroidectomy between January 2013 and January 2018. Patients with FNAB of indeterminate nodules (Bethesda types III, IV, and V) and calculated MTNS were included in the study. Postoperative histopathology was divided into benign and malignant groups. The median and the mean MTNS, the malignancy rate, and the standard deviations were calculated for each subgroup. Of the 344 patient charts reviewed, 106 (30.8%) had an indeterminate FNA biopsy. Eighty-one (76.4%) patients were females and 25 (23.6%) were males. Final pathology revealed malignancy in 69 patients (65.1%). The mean MTNS of patients with malignant pathology (12.81  ± 3.55) was higher than the mean in the benign group (8.32  ± 2.32). 82.4% of thyroid nodules with median MTNS of less than 8 had a benign pathology, and 91.4% of thyroid nodules with median MTNS equal or more than 11 had a malignant pathology (p = 0.002). The rate of malignancy in our series of indeterminate FNABs was 65.1%. The MTNS can be of value to thyroid surgeons in preoperative decision-making when dealing with an indeterminate thyroid nodule.

Prevalence and Associated Factors of Thyroid Incidentaloma among Adult People Attending Gondar University Hospital, Northwest Ethiopia

Background

Incidentally discovered thyroid lesions have become highly common in the development and more frequent utilization of highly sensitive imaging modalities, like ultrasound. However, little is known about its prevalence and associated factors in Ethiopia. The aim of this study was to determine the prevalence of thyroid incidentalomas and associated factors through ultrasound (US) among adults attending Gondar University Hospital.

Methods

A hospital-based cross-sectional study was carried out on 290 adults aged 15 years and above. Out of the adults who visited the hospital during the study, those who neither had history of thyroid disease, thyroid surgery, nor clinically palpable thyroid nodules were involved in the investigation. The participants were examined using a high frequency linear-array transducer (7 MHz). For comparing men and women, the unpaired t-test was used. Binary logistic analysis was used to identify the associated factors, and a P-value < 0.05 was considered statistically significant.

Result

The frequency of thyroid incidentaloma was found to be 33.4% (95% CI: 27.9, 38.9). Thyroid incidentaloma was detected in 42.4% of the females and 22.7% of the males (P<0.001). About 63% had single and 37% multiple thyroid nodules. About 25.8% had thyroid nodules greater than 1cm. In the multivariable logistic regression analysis, increasing age (AOR=5.96; 2.34, 15.15) and female sex (AOR=3.01; 1.73, 5.26) were significantly associated with thyroid incidentalomas.

Conclusion

The frequency of thyroid incidentaloma (TI) was found to be high in this study and much higher among older women. Solitary and small sized thyroid nodules were commonly seen in the study.

Learnability and reproducibility of ACR Thyroid Imaging, Reporting and Data System (TI-RADS) in postgraduate freshmen

PURPOSE

The Thyroid Imaging, Reporting and Data System (TI-RADS) from the American College of Radiology (ACR) has been used since 2017 for the evaluation of thyroid nodules. The purpose of this study is to assess the learnability and reproducibility of TI-RADS in postgraduate freshmen.

METHODS

This was a retrospective study involving 400 nodules with a final diagnosis following ultrasound (US) examination. The nodules were randomized into eight groups (50/group). Three postgraduate freshmen and three experts evaluated the nodules according to ACR TI-RADS without knowledge of the final diagnosis. After evaluating each group, training was carried out based on the inconsistencies of the freshmen/experts. Training was stopped after 200 nodules because the κ value showed almost perfect concordance. Three months later, the 50 nodules of Group 4 (the last evaluated group) were re-evaluated to assess the reproducibility of ACR TI-RADS.

RESULTS

The diagnostic accuracy of the three postgraduate freshmen increased from 60%, 48%, and 46% in Group 1 to 80%, 78%, and 72% in Group 4 (P= 0.029, 0.002, and 0.008), respectively. After training, the diagnostic accuracy of the postgraduate freshmen was close to that of the experts (84%). For the US features, the postgraduate freshmen were consistent with the experts (all κ > 0.6). When re-evaluating Group 4 three months later, the five features had substantial to almost perfect agreement for the same researcher (all κ > 0.7).

CONCLUSION

Based on experts' consensus, ACR TI-RADS can be learned well, and its reproducibility is excellent.

Detection of Thyroid Nodules with Ultrasound Images Based on Deep Learning

BACKGROUND

Thyroid nodules are a common clinical entity with high incidence. Ultrasound is often employed to detect and evaluate thyroid nodules. The development of an efficient automated method to detect thyroid nodules using ultrasound has the potential to reduce both physician workload and operator-dependence.

OBJECTIVES

To study the method of automatic detection of thyroid nodules based on deep learning using ultrasound, and to obtain the detection method with higher accuracy and better performance.

METHODS

A total of 1200 ultrasound images of thyroid nodules and 800 ultrasound thyroid images without nodule are collected. An improved faster R-CNN based detection method of thyroid nodule is proposed. Instead of using VGG16 as the backbone, ResNet is employed as the backbone for faster R-CNN. SVM, CNN and Faster-RCNN methods are used for thyroid nodule detection test. Precision, sensitivity, specificity and F1-score indicators are used to evaluate the detection performance of different methods.

RESULTS

The method based on deep learning is superior to that based on SVM. Faster R-CNN method and the improved method are better than CNN method. Compared with VGG16 as the backbone, RestNet101 backbone based faster R-CNN method achieves better thyroid detection effect. From the accuracy index, the proposed method is 0.084, 0.032 and 0.019 higher than SVM, CNN and faster R-CNN, respectively. Similar results can be seen in precision, sensitivity, specificity and F1-Score indicators.

CONCLUSION

The proposed method of deep learning achieves the best performance values with the highest true positive and true negative detection compared to other methods and performs best in the detection of thyroid nodules.

Thyroid Nodules in Severely Obese Patients: Frequency and Risk of Malignancy on Ultrasonography

Background: We aimed to compare the thyroid ultrasonographic findings of severely obese versus nonobese individuals, and the frequency, characteristics, and risk of malignancy in detected nodules.Design: Case-control study including 67 adults with severe obesity (body mass index [BMI] ≥ 35 kg/m²) and 67 nonobese controls (BMI < 30 kg/m²). The participants underwent ultrasound evaluation of the thyroid and cervical subcutaneous tissue. The risk of malignancy in detected nodules was determined using the American Thyroid Association (ATA) 2015 and the Thyroid Imaging Reporting and Data System (TI-RADS) classifications. Fine-needle aspiration biopsy (FNAB) was performed in nodules for which the procedure was recommended according to the ATA-2015 or TI-RADS criteria, and the cytological evaluation followed the Bethesda classification.Results: The mean BMI values in the case and control groups were 47.0 ± 6.1 kg/m² and 22.8 ± 2.7 kg/m², respectively. There were no differences between groups regarding sex, age, total T3, and antiperoxidase (antiTPO) antibody positivity. When compared with controls, severely obese individuals showed a greater frequency of parenchymal hypoechogenicity (p = 0.042), cervical subcutaneous tissue thickness (p < 0.001), overall frequency of thyroid nodules (p = 0.038), and frequency of multiple nodules (p = 0.013). No significant differences were observed in terms of risk of nodular malignancy according to both the ATA-2015 and TI-RADS classifications in severely obese compared with nonobese individuals.Conclusions: Severely obese individuals (versus nonobese controls) presented increased parenchymal hypoechogenicity and frequency of thyroid nodules on ultrasonographic evaluation. However, no significant differences were observed in terms of risk of nodular malignancy between both groups according to the ATA-2015 and TI-RADS criteria. Thus, ultrasonographic thyroid screening of severely obese individuals is not justified.

Intrathyroidal ectopic thymus in 8-year-old girl: a case report

We provide a case report of two thyroid nodules in an 8-year-old girl, which revealed malignant ultrasonographic findings and which were confirmed as ectopic thymic tissue by total thyroidectomy. The ultrasound presentations of intrathyroidal thymus glands were similar to those of the malignant thyroid nodules. In addition, in this case, there were two ectopic thymus lesions in the thyroid gland, which undoubtedly increased the difficulty of diagnosis. The occurrence of multiple ectopic thymic lesions in the thyroid gland was different from previous reports. Therefore, clinicians should take into consideration this rare entity, and should not mistake it as a thyroid neoplasm; moreover, they should not perform extensive thyroid resection.

Adolescents with thyroid nodules: retrospective analysis of factors predicting malignancy

Thyroid nodules are less common in children than in adults. However, pediatric thyroid nodules have a higher rate of malignancy compared to those in adults, and increased risk of metastasis and recurrence. In the present study, we analyzed the clinical features as well as laboratory and thyroid ultrasound (US) findings of children and adolescents with thyroid nodules to identify predictive factors of thyroid cancer. We retrospectively analyzed 275 patients with thyroid nodules under 18 years of age who visited Severance Children's Hospital between January 2005 and May 2017. Among them, 141 patients who underwent ultrasonography-guided fine needle aspiration biopsy (FNAB), and four patients without FNAB who underwent surgical resection, were included in this study. The remaining 125 patients without FNAB and five patients with follow-up loss after FNAB were excluded. Clinical, laboratory, and US data were evaluated in 145 patients to establish the potential predictive factors of thyroid cancer. Thyroid malignancies were observed in 101 patients. Grade 2 goiters were seen more often in benign nodule group. Hypoechoic nodules, nodules with microcalcifications, abnormal lymph nodes, and irregular margins were findings significantly associated with thyroid cancer. The findings of hypoechoic nodule, nodule with microcalcifications, and abnormal lymph nodes showed statistical significance in predicting thyroid cancer.Conclusion: Hypoechoic nodules, nodules with microcalcifications, and abnormal lymph nodes are predictive factors for thyroid cancer in children. Therefore, further diagnostic evaluations, including FNAB, should be considered in patients with such findings.What is Known:• Thyroid nodules are less common in children than in adults, but pediatric thyroid nodules have a higher rate of malignancy, and also have increased risk of metastasis and recurrence.• Research on ways to predict thyroid cancer have mostly been accomplished in adult patients, and the application of risk stratification system has not been fully satisfactory in children, which requires further studies in pediatric thyroid nodules.What is New:• Hypoechoic nodules, nodules with microcalcifications, and abnormal lymph nodes are predictive factors for thyroid cancer in Korean children.

Taller-Than-Wide Shape: A New Definition Improves the Specificity of TIRADS Systems

INTRODUCTION

A taller-than-wide (TTW) shape is a suspicious feature of thyroid nodules commonly defined as an anteroposterior/transverse diameter (AP/T) ratio >1. An intraobserver variability of up to 18% in AP diameter evaluations has been described, which may lead to overreporting of this feature. To potentially improve the reliability of the TTW definition, we propose an arbitrary ratio of ≥1.2.

OBJECTIVE

The aim of this study was to estimate the impact of this definition on diagnostic performance.

METHODS

We prospectively analyzed 553 thyroid nodules referred for cytology evaluation at an academic center. Before fine-needle aspiration, two examiners jointly defined all sonographic features considered in risk stratification systems developed by the American Thyroid Association (ATA), the American Association of Clinical Endocrinologists (AACE), the American College of Radiology (ACR TIRADS), the European Thyroid Association (EU-TIRADS), and the Korean Society of Thyroid Radiology (K-TIRADS). TTW was defined according to the current definition (AP/T diameter ratio >1) and an arbitrary alternative definition (AP/T ratio >1.2).

RESULTS

The alternative definition classified fewer nodules as TTW (28, 5.1% vs. 94, 17%). The current and proposed definitions have a sensitivity of 26.2 and 11.9% (p = 0.03) and a specificity of 83.8 and 95.5% (p < 0.001). Thus, as a single feature, the arbitrary definition has a lower sensitivity and a higher specificity. When applied to sonographic risk stratification systems, however, the proposed definition would increase the number of avoided biopsies (up to 58.2% for ACR TIRADS) and the specificity of all systems, without negative impact on sensitivity or diagnostic odds ratio.

CONCLUSIONS

Re-defining TTW nodules as those with an AP/T ratio ≥1.2 improves this marker's specificity for malignancy. Using this definition in risk stratification systems will increase their specificity, reducing the number of suggested biopsies without significantly diminishing their overall diagnostic performance.

Intravoxel incoherent motion and ADC measurements for differentiating benign from malignant thyroid nodules: utilizing the most repeatable region of interest delineation at 3.0 T

Background

There is a growing need for a reproducible and effective imaging method for the quantitative differentiation of benign from malignant thyroid nodules. This study aimed to investigate the performances of intravoxel incoherent motion (IVIM) parameters and the apparent diffusion coefficient (ADC) in differentiating malignant from benign thyroid nodules derived from the most repeatable region of interest (ROI) delineation.

Methods

Forty-three patients with 46 pathologically confirmed thyroid nodules underwent diffusion-weighted imaging (DWI) with 8 b values. Two observers measured the intravoxel incoherent motion (IVIM) parameters (D, f and D*) and the apparent diffusion coefficient (ADC), ADC₆₀₀ and ADC₉₉₀ values using whole-lesion (W-L) ROI and IVIM parameters using single-section (S-S) ROI delineation. The intraclass correlation coefficients (ICCs) and Bland-Altman plots were used to evaluate the intra- and interobserver variability. The diagnostic performance of these parameters was evaluated by generating receiver operating characteristic (ROC) curves.

Results

The ICC values of all IVIM with W-L ROI delineation were higher than those with S-S ROI delineation, and excellent intra- and interobserver reproducibility was obtained. According to the Bland-Altman plots, the 95% limits of agreement of the IVIM parameters determined by the W-L ROIs revealed smaller absolute intra- and interobserver variability than those determined by S-S ROIs. The D and ADC₆₀₀ values obtained from the W-L ROIs were the most powerful parameters in differentiating benign from the malignant nodules [area under the ROC curve = 0.962 and 0.970, P = 0.771].

Conclusions

The W-L ROI of the thyroid was considered an effective method for obtaining IVIM measurements with excellent reproducibility for differentiating benign from malignant nodules.

2019 Practice guidelines for thyroid core needle biopsy: a report of the Clinical Practice Guidelines Development Committee of the Korean Thyroid Association

Ultrasound-guided core needle biopsy (CNB) has been increasingly used for the pre-operative diagnosis of thyroid nodules. Since the Korean Society of the Thyroid Radiology published the ‘Consensus Statement and Recommendations for Thyroid CNB’ in 2017 and the Korean Endocrine Pathology Thyroid CNB Study Group published ‘Pathology Reporting of Thyroid Core Needle Biopsy’ in 2015, advances have occurred rapidly not only in the management guidelines for thyroid nodules but also in the diagnostic terminology and classification schemes. The Clinical Practice Guidelines Development Committee of the Korean Thyroid Association (KTA) reviewed publications on thyroid CNB from 1995 to September 2019 and updated the recommendations and statements for the diagnosis and management of thyroid nodules using CNB. Recommendations for the resolution of clinical controversies regarding the use of CNB were based on expert opinion. These practical guidelines include recommendations and statements regarding indications for CNB, patient preparation, CNB technique, biopsy-related complications, biopsy specimen preparation and processing, and pathology interpretation and reporting of thyroid CNB.

Diagnosis and treatment of thyroid nodules in Spain. Results of a national survey

INTRODUCTION

Thyroid nodule (TN) is a common reason for consultation in daily practice. The purpose of this study was to evaluate the diagnosis and treatment of TNs in our environment and to assess the current status regarding the existence and structure of high-resolution TN clinics.

MATERIAL AND METHODS

Members of the Spanish Society of Endocrinology and Nutrition were invited in 2018 to participate in an online survey on the diagnostic and therapeutic processes of TN.

RESULTS

A total of 211 valid surveys were received. Of all respondents, 30.8% stated that there were high-resolution TN clinics in their environment, with the endocrinologist being the main person responsible for performing ultrasonography (87.7%) and fine needle aspiration (FNA) (69.2%). For ultrasound classification of TNs, 32.7% used the ATA criteria, 32.2% the TI-RADS criteria, and 22.7% no classification. In situ verification of sample suitability was performed in 35.5% of the cases, and molecular analysis in 8.1%. With regard to clinical discharge, 65.4% would consider it after 5 years of follow-up and with a benign FNA. In the event of a Bethesda III result, 50.2% of respondents would repeat FNA and 35.5% would opt for surgery; if a Bethesda IV result was found, 95.8% would opt for surgery.

CONCLUSIONS

High-resolution TN clinics are structures increasingly implemented in our environment where the endocrinologist is the main person responsible for performing ultrasonography and FNA. The standard clinical practice in our specialty is consistent with most recommendations concerning clinical practice guidelines for TNs.

Cervical lymph nodes, a diagnostic dilemma

Cervical lymph nodes could be a starting sign for a complex diagnosis work-up. Depending on co-morbidities, medical unit and physician's previous experience, the differential diagnosis includes thyroid malignancy, lymphoma, chronic infectious disorders, etc.

Recognition of calcifications in thyroid nodules based on attention-gated collaborative supervision network of ultrasound images

BACKGROUND

Calcification is an important criterion for classification between benign and malignant thyroid nodules. Deep learning provides an important means for automatic calcification recognition, but it is tedious to annotate pixel-level labels for calcifications with various morphologies.

OBJECTIVE

This study aims to improve accuracy of calcification recognition and prediction of its location, as well as to reduce the number of pixel-level labels in model training.

METHODS

We proposed a collaborative supervision network based on attention gating (CS-AGnet), which was composed of two branches: a segmentation network and a classification network. The reorganized two-stage collaborative semi-supervised model was trained under the supervision of all image-level labels and few pixel-level labels.

RESULTS

The results show that although our semi-supervised network used only 30% (289 cases) of pixel-level labels for training, the accuracy of calcification recognition reaches 92.1%, which is very close to 92.9% of deep supervision with 100% (966 cases) pixel-level labels. The CS-AGnet enables to focus the model's attention on calcification objects. Thus, it achieves higher accuracy than other deep learning methods.

CONCLUSIONS

Our collaborative semi-supervised model has a preferable performance in calcification recognition, and it reduces the number of manual annotations of pixel-level labels. Moreover, it may be of great reference for the object recognition of medical dataset with few labels.

Laser photocoagulation therapy for thyroid nodules: long-term outcome and predictors of efficacy

PURPOSE

The aim of the present study was to retrospectively evaluate the efficacy of interstitial laser photocoagulation (ILP) ablation of thyroid nodules during a 6-year follow-up period and to identify possible predictors of the final outcome.

METHODS

Forty-three outpatients (38 women) were assigned to ILP therapy. The study group included euthyroid patients with benign thyroid nodules. Thyroid size, nodule volume and features, and autoimmune test were collected at baseline. Patients underwent US control after the ILP procedure and 1 month, 6 months, 12 months later and then annually.

RESULTS

During the follow-up, two distinct groups of patients emerged: the responders (N = 33) and the non-responder (N = 10) ones to ILP. In the responder group, the nodule volume significantly decreased during the follow-up, but a trend toward a slight increase in nodule volume was recorded up to the end of follow-up. No significant decrease in nodule volume was observed in the non-responder group. Neither baseline clinical nor demographic features were significantly different between responders and non-responders groups. In the whole group of patients, the energy delivered per mL of nodule tissue was significantly correlated with the percent volume decrease at the end of follow-up.

CONCLUSIONS

Interstitial laser photocoagulation is a safe technique able to reduce byabout 50% the volume of benign thyroid nodules in the majority of treated patients. However, due to the great variability of results, an active follow-up is required. The only independent predictor of ILP outcome is the energy delivered per mL of nodule tissue.

Association between thyroid nodule size and malignancy rate

INTRODUCTION

The diagnostic performance of ultrasound-fine needle aspiration to identify thyroid nodules harbouring malignancy remains variable. The aim of this study was to determine thyroid nodule size and cytological classification as predictors of malignancy risk.

MATERIALS AND METHODS

We conducted a retrospective cohort analysis at an academic hospital involving 499 consecutive patients who underwent thyroid surgery between 2004 and 2015.

RESULTS

A total of 503 thyroid nodules (499 patients, 84% female; mean age 50.8 years, standard deviation, SD, 15.4 years) were analysed. Of these, 19.5% were malignant. The mean (± SD) nodule size was 3.28 ± 1.63 cm and 3.27 ± 1.54 cm for benign and malignant nodules, respectively. The odds of malignancy for thyroid nodules less than 3.0 cm was similar to those for nodules of 3.0 cm or greater (0.26 compared with 0.29; p=0.77). Overall, the sensitivity and specificity of fine-needle aspiration in this cohort were 71.4% and 100%, respectively. The overall false negative rate was 5.4%. When the cut-off of 3.0 cm was used, the false negative rate in thyroid nodules less than 3.0 cm was 0% compared with 7.0% in nodules of 3.0 cm or greater. Thus, class (p<0.01) but not nodule size (p=0.49), was associated with higher malignancy risk.

CONCLUSIONS

Our results suggest that thyroid nodule size did not accurately predict the risk of thyroid malignancy irrespective of fine-needle aspiration cytology. Routine diagnostic thyroid lobectomy solely owing to thyroid nodule size of 3.0 cm or greater is currently not justified.

Thyroid nodule prevalence among women in areas of high natural background radiation, Karunagappally, Kerala, India

PURPOSE

Radiation exposure has been reported to cause thyroid nodules. The study area was Karunagapally, which has several areas with high natural radiation levels derived from thorium and its decay products. Since thyroid abnormalities are more common in women, the focus was only on women.

METHODS

The examinations included interview, ultrasonography of the thyroid and serum assays of free thyroxine (FT4), thyrotropin (TSH), and anti-thyroglobulin levels. Cumulative dose during the childhood and lifetime cumulative dose (lagged by 5 years) were estimated.

RESULTS

We examined 524 female residents aged 17-73 years and found 75 cases of solitary solid thyroid nodules. The prevalence of thyroid nodules were 14.1 % (n = 42) in high dose panchayats and 14.5% (n = 33) in low-dose panchayats. In the logistic regression analysis adjusted for age, the prevalence of solitary thyroid nodule was not linearly related to childhood cumulative dose (P for trend = 0.159) and lifetime cumulative dose (P for trend = 0.333). The prevalence of thyroiditis and hypothyroidism was not related to natural radiation exposure. Serum levels of FT4 or TSH were not related to natural radiation exposure.

CONCLUSIONS

The results obtained from the present study do not support the increase of solitary thyroid nodule, thyroiditis or hypothyroidism in relation to high-natural-background-radiation exposure.

Interobserver agreement and efficacy of consensus reading in Kwak-, EU-, and ACR-thyroid imaging recording and data systems and ATA guidelines for the ultrasound risk stratification of thyroid nodules

PURPOSE

To investigate the interobserver agreement (IA) and the impact of consensus reading using four risk stratification systems for thyroid nodules (TN).

METHODS

Four experienced specialists independently rated US images of 80 TN according to the Kwak-TIRADS, EU-TIRADS, ACR TI-RADS, and ATA Guidelines. The cases were randomly extracted from a prospectively acquired database (n > 1500 TN). The observers were blinded to clinical data. This study was divided into two sessions (S1 and S2) with 40 image sets each. After every session, a consensus reading was carried out (C1, C2). Subsequently, the effect of C1 was tested in S2 with 40 new cases followed by C2. Fleiss' kappa (κ) was calculated for S1 and S2 to estimate the IA and learning curves. The results of C1 and C2 were used as reference for diagnostic accuracy calculations.

RESULTS

IA significantly increased (p < 0.01) after C1 with κ values of 0.375 (0.615), 0.411 (0.596), 0.321 (0.569), and 0.410 (0.583) for the Kwak-TIRADS, EU-TIRADS, ACR TI-RADS, and ATA Guidelines in S1 (S2), respectively. ROC analysis (C1 + C2) revealed similar areas under the curve (AUC) for the Kwak-TIRADS, EU-TIRADS, ACR TI-RADS, and ATA Guidelines (0.635, 0.675, 0.694, and 0.654, respectively, n.s.). AUC did not increase from C1 (0.677 ± 0.010) to C2 (0.632 ± 0.052, n.s.). ATA Guidelines were not applicable in five cases.

CONCLUSIONS

IA and diagnostic accuracy were very similar for the four investigated risk stratification systems. Consensus reading sessions significantly improved the IA but did not affect the diagnostic accuracy.